Basement conversions: why Londoners are digging deep

Extra bedroom? A car park for the Ferrari? With space in the capital at a
premium, Londoners are creating ever more impressive – and expensive–
basements.

How low can you go? Marek Bilinski at the Fairholt Street conversionPhoto: Clara Molden

By Harry de Quetteville

8:00AM GMT 25 Feb 2013

Direction of travel is a huge thing in life. Are you moving up? Or have you been pushed sideways? Chances are these days, if you are the space-starved owner of a London house, you are going down. That used to be a bad thing, with the implication that you were off to spend some time at Her Majesty's pleasure.

Not any more. At least, if the vans, diggers, skips, parking restriction orders, pumps, rubble-bearing conveyor belts, dust and noise that feature on virtually every London street are anything to go by. Moving down in the world has, it seems, become highly desirable. In one short decade we have become a city of basement builders. A metropolis of moles.

Not since the Victorian era have we excavated so thoroughly and determinedly beneath our feet. But where bygone engineers hewed out an infrastructure of sewers and Tube tunnels for the public good, their modern counterparts are doing it for themselves. Some are doing it for their families. Others are mining to create steam rooms and saunas, gold-tiled pools and secure parking for classic car collections.

The effect is startling. A blink of an eye ago, leisure-heavy lovelies propping up London's wealthiest men had to "pop out" to the gym or the hairdresser. No longer. Anyone who is anyone "pops down".

As in: "I think I'll pop down to the cinema to watch Sex in the City". Or "I'm just going to pop down and make sure the ballroom is ready for the guests." Or – and believe me, these places do exist – "Shall we pop down and have a quick set of tennis?"

In prime central London, where houses routinely change hands for many millions, that last phrase is likely to be in another language: Arabic or Russian. According to William Duckworth-Chad, a director at Savills, two thirds of houses sold for more than £5 million in central London in the past two years went to buyers from abroad.

But one thing unites all basement-builders: the need for space. Whether super-rich sultans or stressed-out suburbanites, we all want more of it. And in this great city there simply isn't much to go around. So, despite the huge variation in budgets, every prospective caveman or woman has to answer the same questions.

What can be done? How can it be done well? And does it make financial sense? Most eye-catching are without doubt those projects on which millions have been lavished. "I've seen everything from basement nightclubs, to bowling alleys, golf ranges and private car collections," adds Duckworth-Chad.

And that's before actual living space is taken into account. Not that the super-rich live in basement bedrooms. But you have to put the staff somewhere.

Of course, with planning laws strictly regulating upward expansion, the desire to dig can get out of hand. Duckworth-Chad says that, while planners are "wising up", in the recent past there has been nothing to stop millionaire moles "drilling down to the South Pole". Kensington and Chelsea alone has seen 800 planning applications for basements in the past five years. Only 10 per cent are rejected, and those are almost always resubmitted.

As a result the city's smartest addresses are regularly afflicted by residents falling out over basement schemes. The latest is the battle between the Daimler-Benz heir Gert-Rudolph "Muck" Flick and his neighbours, led by the cellist Julian Lloyd Webber.

Flick and his third wife, the German heiress Corinne, want to create a seven-metre deep basement for a pool and steam room underneath their Georgian home in South Kensington. But their plans have come up against some opposition. Other basement-building owners in the area became so unpopular that they were sent a letter by a neighbour telling them that he intended to acquire their house by hook or crook, rip it down and let sheep graze on the ruins.

Not far away, on Fairholt Street, in Knightsbridge, Savills has a spectacular property on the market for £5.65 million (020 7590 5059). It was bought in mid-2011 by the developers Florio Bilinski when it occupied just 1,426sq ft.

Over 12 months it was extended through a double basement to 2,272sq ft, transforming a pied-à-terre into a town house.

The double basement is far from dingy. It obeys the most crucial law of digging: there is no point having extra space if it is miserable, claustrophobic and dark.

"Ceiling height is crucial," says Marek Bilinski. "That and natural light. So skylights and windows are essential. They deliver space that you actually want to use."

At Fairholt Street, the basement ceilings are 3.5m and 2.5m high. Though the project was challenging, it will be worth it. The cost of development was between £600-£800 per square foot, on top of an acquisition cost in the region of £1,500 per square foot. Properties in the area can sell for up to £2,500 per square foot.

Indeed, Bilinski says, the building work was not the hardest part of the development. Between the council, the neighbours and Bilinski's own experts, he says, there were "five sets of lawyers and five sets of engineers" to deal with.

"It can be long, drawn out and expensive. Party walls can hold you back for months." Where, 10 years ago, at the beginning of the basement boom, a handshake may have been enough to guarantee good behaviour, now nothing less than a cash deposit in an escrow account will satisfy those who fear that something might go wrong.

Getting on with the neighbours is no less important for those beyond "prime central" London. But there the emphasis is less on Ferraris and more on families.

Amanda Mills, 52, and her husband, Charlie, 55, moved to Balham, south-west London, when their three children were still young. Eight years ago they added a basement, which cost them £130,000 plus VAT for five months' work. Everything went well until a neighbour called round one Saturday morning to complain about the noise.

But once the dust had settled, the basement proved invaluable. It was what Mills calls "a different kind of space" – an indestructible indoor room, where a football could be kicked against a wall, and the children could be left to play with their friends.

"Each child in turn has had masses of friends back," she says. "I felt at one point that because of the basement, ours was the house that everyone wanted to come to. We could shut the door on the noise, which meant we didn't get angry."

But does harmony in the home translate into hard cash? The Mills family have put their stunning home on the market for £2.39m through Knight Frank's Wandsworth office (020 8682 7777) and are hoping that their basement will prove a major selling point. Best estimates suggest that an underground room or rooms can add 10 to 15 per cent value to a house, perhaps 20 per cent in central London. But only if they are done well. It certainly remains cheaper to build more space than to buy a bigger house.

There are alternatives to burrowing, of course. Conservatories, garden rooms and loft extensions probably come first. Only then might it be time to call in the diggers.

Once you get through the hassle, you'll almost certainly find that as the final van drives away, of course, your peace will be shattered by the sound of drilling.

Yep – it will be the neighbours, having decided that if you can't beat them, join them. £Be considerate with your proposal and try to minimise disruption to the neighbours.

The low-down

Keep your basement in proportion to the size of the house. A maximum of 25 per cent of the above-ground floorspace is about right

Natural light and ceiling heights are key. Sun pipes and lightwells bounce light down into the basement